Quality of life from a randomized trial of open and endovascular repair for abdominal aortic aneurysm

Background

Long-term survival is similar after open or endovascular repair of abdominal aortic aneurysm. Few data exist on the effect of either procedure on long-term health-related quality of life (HRQoL) and health status.

Methods

Patients enrolled in a multicentre randomized clinical trial (DREAM trial; 2000–2003) in Europe of open repair versus endovascular repair (EVAR) of abdominal aortic aneurysm were asked to complete questionnaires on health status and HRQoL. HRQoL scores were assessed at baseline and at 13 time points thereafter, using generic tools, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36®) and EuroQol 5D (EQ-5D™). Physical (PCS) and mental component summary scores were also calculated. Follow-up was 5 years.

Results

Some 332 of 351 patients enrolled in the trial returned questionnaires. More than 70 per cent of questionnaires were returned at each time point. Both surgical interventions had a short-term negative effect on HRQoL and health status. This was less severe in the EVAR group than in the open repair group. In the longer term the physical domains of SF-36® favoured open repair: mean difference in PCS score between open repair and EVAR −1·98 (95 per cent c.i. −3·56 to −0·41). EQ-5D™ descriptive and EQ-5D™ visual analogue scale scores for open repair were also superior to those for EVAR after the initial 6-week interval: mean difference −0·06 (−0·10 to −0·02) and −4·09 (−6·91 to −1·27) respectively.

Conclusion

In this study EVAR appeared to be associated with less severe disruption to HRQoL and health status in the short term. However, during longer-term follow-up to 5 years, patients receiving open repair appeared to have improved quality of life and health status.

[Treatment of abdominal aortic aneurysm: is there still a place for open repair?]

Due to lower peri-operative mortality, lower risk of complications and shorter duration of hospital stay, endovascular aneurysm repair has become preferential treatment for an infrarenal aortic aneurysm. Three randomised studies that compared endovascular repair with open repair now report follow-up data of an average of six years. The data shows a loss of peri-operative mortality advantage after two to three years. More re-interventions are performed following endovascular treatment. The predominant cause of death is due to cardiovascular events, for which optimal medical therapy is crucial. The initial mortality advantage of endovascular aneurysm repair compared to open repair is lost sooner in elderly and high-risk patients than in those patients who are relatively young and low-risk.

Interleukin-6 receptor pathways in abdominal aortic aneurysm

METHODS

We conducted a systematic review and meta-analysis of studies reporting circulating IL-6 in AAA, and new investigations of the association between a common non-synonymous functional variant (Asp358Ala) in the IL-6R gene (IL6R) and AAA, followed the analysis of the variant both in vitro and in vivo. Inflammation may play a role in the development of abdominal aortic aneurysms (AAA). Interleukin-6 (IL-6) signalling through its receptor (IL-6R) is one pathway that could be exploited pharmacologically. We investigated this using a Mendelian randomization approach.

RESULTS

Up to October 2011, we identified seven studies (869 cases, 851 controls). Meta-analysis demonstrated that AAA cases had higher levels of IL-6 than controls [standardized mean difference (SMD) = 0.46 SD, 95% CI = 0.25-0.66, I(2) = 70%, P = 1.1 × 10-5 random effects]. Meta-analysis of five studies (4524 cases/15 710 controls) demonstrated that rs7529229 (which tags the non-synonymous variant Asp358Ala, rs2228145) was associated with a lower risk of AAA, per Ala358 allele odds ratio 0.84, 95% CI: 0.80-0.89, I(2) = 0%, P = 2.7 × 10-11). In vitro analyses in lymphoblastoid cell lines demonstrated a reduction in the expression of downstream targets (STAT3, MYC and ICAM1) in response to IL-6 stimulation in Ala358 carriers.

CONCLUSIONS

A Mendelian randomization approach provides robust evidence that signalling via the IL-6R is likely to be a causal pathway in AAA. Drugs that inhibit IL-6R may play a role in AAA management.

A Variant in LDLR Is Associated With Abdominal Aortic Aneurysm

Background—

Abdominal aortic aneurysm (AAA) is a common cardiovascular disease among older people and demonstrates significant heritability. In contrast to similar complex diseases, relatively few genetic associations with AAA have been confirmed. We reanalyzed our genome-wide study and carried through to replication suggestive discovery associations at a lower level of significance.

Methods and Results—

A genome-wide association study was conducted using 1830 cases from the United Kingdom, New Zealand, and Australia with infrarenal aorta diameter ≥30 mm or ruptured AAA and 5435 unscreened controls from the 1958 Birth Cohort and National Blood Service cohort from the Wellcome Trust Case Control Consortium. Eight suggestive associations with P <1×10 −4 were carried through to in silico replication in 1292 AAA cases and 30 503 controls. One single-nucleotide polymorphism associated with P <0.05 after Bonferroni correction in the in silico study underwent further replication (706 AAA cases and 1063 controls from the United Kingdom, 507 AAA cases and 199 controls from Denmark, and 885 AAA cases and 1000 controls from New Zealand). Low-density lipoprotein receptor ( LDLR ) rs6511720 A was significantly associated overall and in 3 of 5 individual replication studies. The full study showed an association that reached genome-wide significance (odds ratio, 0.76; 95% confidence interval, 0.70–0.83; P =2.08×10 −10 ).

Conclusions—

LDLR rs6511720 is associated with AAA. This finding is consistent with established effects of this variant on coronary artery disease. Shared causal pathways with other cardiovascular diseases may present novel opportunities for preventative and therapeutic strategies for AAA.

Renal function 5 years after open and endovascular aortic aneurysm repair from a randomized trial

Background

Deterioration of renal function after major vascular surgery is an important complication, and may vary between patients undergoing endovascular (EVAR) or open surgical (OR) repair of an abdominal aortic aneurysm (AAA). The objective was to determine the impact of OR and EVAR on renal function after 5 years.

Methods

This was a post hoc analysis of data collected prospectively from the Dutch Randomized Endovascular Aneurysm Management (DREAM) trial. Five years after surgery, creatinine levels were available for 189 patients (94 after OR and 95 after EVAR). The severity of renal disease was staged using the chronic kidney disease classification of the US National Kidney Foundation clinical guidelines.

Results

Using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, the estimated glomerular filtration rate (eGFR) for the entire group declined over time, with a mean(s.d.) preoperative value of 80·0(7·6) ml per min per 1·73 m2 compared with 75·7(9·7) ml per min per 1·73 m2 after 5 years (mean difference 4·2 (95 per cent confidence interval 3·2 to 5·3) ml per min per 1·73 m2; P &lt; 0·001). Five years after surgery, the mean eGFR (CKD-EPI equation) was not significantly different between the OR and EVAR groups: 76·3(9·3) versus 75·1(10·0) ml per min per 1·73 m2 (mean difference 1·2 (−1·6 to 3·9) ml per min per 1·73 m2; P = 0·410).

Conclusion

Renal function 5 years after OR and EVAR for AAA was similar. Neither surgical procedure accelerated the loss of renal function. Registration number: NCT00421330 (http://www.clinicaltrials.gov).

A sequence variant associated with sortilin-1 (SORT1) on 1p13.3 is independently associated with abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a common human disease with a high estimated heritability (0.7); however, only a small number of associated genetic loci have been reported to date. In contrast, over 100 loci have now been reproducibly associated with either blood lipid profile and/or coronary artery disease (CAD) (both risk factors for AAA) in large-scale meta-analyses. This study employed a staged design to investigate whether the loci for these two phenotypes are also associated with AAA. Validated CAD and dyslipidaemia loci underwent screening using the Otago AAA genome-wide association data set. Putative associations underwent staged secondary validation in 10 additional cohorts. A novel association between the SORT1 (1p13.3) locus and AAA was identified. The rs599839 G allele, which has been previously associated with both dyslipidaemia and CAD, reached genome-wide significance in 11 combined independent cohorts (meta-analysis with 7048 AAA cases and 75 976 controls: G allele OR 0.81, 95% CI 0.76-0.85, P = 7.2 × 10(-14)). Modelling for confounding interactions of concurrent dyslipidaemia, heart disease and other risk factors suggested that this marker is an independent predictor of AAA susceptibility. In conclusion, a genetic marker associated with cardiovascular risk factors, and in particular concurrent vascular disease, appeared to independently contribute to susceptibility for AAA. Given the potential genetic overlap between risk factor and disease phenotypes, the use of well-characterized case-control cohorts allowing for modelling of cardiovascular disease risk confounders will be an important component in the future discovery of genetic markers for conditions such as AAA.

A gene-centric study of common carotid artery remodelling

Background

Expansive remodelling is the process of compensatory arterial enlargement in response to atherosclerotic stimuli. The genetic determinants of this process are poorly characterized.

Methods

Genetic association analyses of inter-adventitial common carotid artery diameter (ICCAD) in the IMPROVE study (n = 3427) using the Illumina 200k Metabochip was performed. Single nucleotide polymorphisms (SNPs) that met array-wide significance were taken forward for analysis in three further studies (n = 5704), and tested for association with Abdominal Aortic Aneurysm (AAA).

Results

rs3768445 on Chromosome 1q24.3, in a cluster of protein coding genes (DNM3, PIGC, C1orf105) was associated with larger ICCAD in the IMPROVE study. For each copy of the rare allele carried, ICCAD was on average 0.13 mm greater (95% CI 0.08–0.18 mm, P = 8.2 × 10⁻⁸). A proxy SNP (rs4916251, R² = 0.99) did not, however, show association with ICCAD in three follow-up studies (P for replication = 0.29). There was evidence of interaction between carotid intima-media thickness (CIMT) and rs4916251 on ICCAD in two of the cohorts studies suggesting that it plays a role in the remodelling response to atherosclerosis. In meta-analysis of 5 case–control studies pooling data from 5007 cases and 43,630 controls, rs4916251 was associated with presence of AAA 1.10, 95% CI 1.03–1.17, p = 2.8 × 10⁻³, I² = 18.8, Q = 0.30). A proxy SNP, rs4916251 was also associated with increased expression of PIGC in aortic tissue, suggesting that this may the mechanism by which this locus affects vascular remodelling.

Conclusions

Common variation at 1q24.3 is associated with expansive vascular remodelling and risk of AAA. These findings support a hypothesis that pathways involved in systemic vascular remodelling play a role in AAA development.

A high prevalence of carotid artery stenosis in male patients older than 65 years, irrespective of presenting clinical manifestation of atherosclerotic diseases

This study investigated the prevalence of carotid artery stenosis (CS) and the association with various risk factors in male patients (>65 years) diagnosed with cardiovascular diseases. Duplex sonography of the carotid arteries was performed in 434 of 473 eligible patients of whom 118 (27.8%) patients had significant CS ≥50%. The prevalence and severity of CS did not differ between patients who presented with neurological symptoms or acute coronary syndrome/peripheral artery disease (30.8% vs 25.9%, respectively). Among patients with CS, a higher rate of current smoking, a higher systolic blood pressure, and a lower glomerular filtration rate were observed compared with patients without CS. A history of coronary artery bypass graft was a significant predictor of the presence of CS (P = .003, odds ratio [OR] = 2.70 [1.40-5.19]). The prevalence of CS in elderly males with manifest atherosclerotic disease is high, irrespective of presenting clinical manifestation.

Residual infrarenal aortic neck following endovascular and open aneurysm repair

BACKGROUND

The effectiveness of open and endovascular aneurysm repair of aortic abdominal aneurysms (AAAs) can be jeopardised by deterioration of the residual infrarenal neck of the aneurysm.

OBJECTIVE

The study aims to determine the length of the residual infrarenal aortic segment after endovascular and open aneurysm repair.

METHODS

In a multicentre randomised controlled trial comparing open and endovascular AAA repair, 165 patients were discharged after open AAA repair (OR) and 169 after endovascular repair (EVAR). Immediately after the operation, surgeons were asked to enter in the case record form whether the level of their anastomosis after open repair was within or beyond 10 mm of the caudal renal artery. Postoperative computed tomography (CT) scans that were obtained within 6 months after surgery were used for comparative analysis. The distance between the caudal renal artery and the proximal anastomosis of the (endo-) graft was measured using axial CT slices and a standardised protocol. CT images were available and suitable for analysis in 156 (95%) of 165 OR patients and in 160 (95%) of 169 EVAR patients. Data are presented as median (range). Differences were analysed using the Mann-Whitney test.

RESULTS

The distance from the caudal renal artery to the proximal anastomosis was 24 mm (16-30 mm) in the OR group versus 0 mm (0-6 mm) in the EVAR group (p < 0.0001, Mann-Whitney). In 140 of 156 (90%) patients, at least 1 cm of untreated infrarenal neck persisted after OR and in 17 of 160 (10%) after EVAR. In 84 of the 156 open repair patients (54%), the surgeon had indicated that the proximal anastomosis was within 10 mm of the caudal renal artery. Only five surgeons (6%) were accurate in this respect.

CONCLUSION

After open repair, a longer segment of the infrarenal aortic neck is left untreated compared with endovascular repair and this length is underestimated by most surgeons. Long-term studies are required to determine the consequences of this difference.

Decision making in AAA repair in 2012: open or endo?

With data from four randomized trials on elective endovascular abdominal aortic aneurysm repair and many more additional post-hoc publications, the evidence can be somewhat overwhelming for the surgeon, let alone the patient. This chapter aims to present the most recent and relevant data for decision making in abdominal aortic aneurysm (AAA) repair in a comparative and concise format. After a comparison of the short- and long-term survival data of the randomized trials, the following post-hoc analyses of the four randomized trials will be presented: causes of death, reinterventions, renal function, prediction of complications, and quality of life. When both open and endovascular repair are a reasonable option for an individual patient, we need to objectively inform our patient about the available evidence from the trials. The three-fold reduction of operative mortality with endovascular repair as compared to open repair should be presented. Next, the convergence of the overall survival curves should be discussed as a key factor in the decision process. The counterintuitive observation may be considered that if endovascular repair is better for any specific subgroup it is for younger patients with low surgical risks. Finally, the patient needs to understand that the risks of reintervention and complications are higher after endovascular than after open repair and that this is even more relevant in older patients with larger aneurysms. The information that the quality of life advantage of endovascular repair is only short lived and for several domains surpassed by open repair is most likely not suitable for direct discussion with the individual patient, but it may put the procedures in the right perspective for the physician and health care managers.

Meta-analysis of the association between single nucleotide polymorphisms in TGF-β receptor genes and abdominal aortic aneurysm

OBJECTIVE

The role of transforming growth factor (TGF)-beta in abdominal aortic aneurysm (AAA) is controversial. The aim of this study was to assess the association of single nucleotide polymorphisms (SNPs) within TGFBR1 and TGFBR2 with AAA and infrarenal aortic diameter by combining data from previously published studies.

METHODS

We performed a meta-analysis using individual subject data from three independent case-control groups from Western Australia (n=1675), New Zealand (n=1209), and the Netherlands (n=1636) with 610, 601, and 693 cases of AAA (maximum infrarenal aortic diameter ≥30 mm), respectively. Data were available for two TGFBR1 (rs10819634, rs1571590) and six TGFBR2 (rs304839, rs1346907, rs1036095, rs9831477, rs9843143, rs764522) SNPs.

RESULTS

There was marked heterogeneity between studies. The G alleles of the TGFBR2 rs764522 and rs1036095 SNPs were associated with AAA under a recessive model (OR=1.69, 95% CI 1.28-2.25, P<0.001 and OR=1.59, 95% CI 1.23-2.07, P<0.001) when a fixed effects model was used. Both associations remained significant after adjustment for multiple testing.

CONCLUSION

This study suggests that two common genetic polymorphisms in TGFBR2 are associated with the risk of developing AAA although this association was mainly driven by findings in the Netherlands group and marked between study heterogeneity was detected.

Long-term outcome of open or endovascular repair of abdominal aortic aneurysm

BACKGROUND

For patients with large abdominal aortic aneurysms, randomized trials have shown an initial overall survival benefit for elective endovascular repair over conventional open repair. This survival difference, however, was no longer significant in the second year after the procedure. Information regarding the comparative outcome more than 2 years after surgery is important for clinical decision making.

METHODS

We conducted a long-term, multicenter, randomized, controlled trial comparing open repair with endovascular repair in 351 patients with an abdominal aortic aneurysm of at least 5 cm in diameter who were considered suitable candidates for both techniques. The primary outcomes were rates of death from any cause and reintervention. Survival was calculated with the use of Kaplan-Meier methods on an intention-to-treat basis.

RESULTS

We randomly assigned 178 patients to undergo open repair and 173 to undergo endovascular repair. Six years after randomization, the cumulative survival rates were 69.9% for open repair and 68.9% for endovascular repair (difference, 1.0 percentage point; 95% confidence interval [CI], -8.8 to 10.8; P=0.97). The cumulative rates of freedom from secondary interventions were 81.9% for open repair and 70.4% for endovascular repair (difference, 11.5 percentage points; 95% CI, 2.0 to 21.0; P=0.03).

CONCLUSIONS

Six years after randomization, endovascular and open repair of abdominal aortic aneurysm resulted in similar rates of survival. The rate of secondary interventions was significantly higher for endovascular repair. (ClinicalTrials.gov number, NCT00421330.)

Validation of the Simulator for Testing and Rating Endovascular SkillS (STRESS)-machine in a setting of competence testing

AIM

Endovascular skills are an integral part of modern-day vascular surgery. The STRESS machine has been developed to test these skills in vascular surgeons. This study aims to define an optimal pass/fail cutoff value for the STRESS test score.

METHODS

The STRESS machine consists of a dry glass model of the abdominal aorta and its tributaries with various stenotic lesions, elongations, and tortuosities. A camera and computer software are used to simulate plain fluoroscopy-mode. The test subjects are given two assignments after which two reviewers use a combination of the ICEPS and MRS to produce the final total score; 43 subjects were tested. According to previous endovascular experience, subjects were classified into four groups: novice-low (no experience, less than 11 performed procedures, less than 50 assisted procedures), novice-high (11-25 performed procedures, more than 50 assisted procedures), intermediate (1-10 performed and >11-25 assisted procedures, 11-25 performed and >1-10 assisted procedures or 25-50 performed procedures) and advanced (more than 50 performed procedures).

RESULTS

Test-score and noted experience showed a correlation of 0.794. All intermediate and advanced test subjects scored more than 50 points compared to 4 out of 15 novices.

CONCLUSION

We demonstrated that it is possible to determine an optimal cut-off value for competence testing with the STRESS machine.